JPS61287009A - Rotary head type recorder - Google Patents

Abstract

PURPOSE:To decrease the adverse effect on a recording signal and to reduce the power consumption by switching the supply quantity of an erasure current to a rotary erasure head in switching the running speed of a tape recording medium in the lengthwise direction. CONSTITUTION:An erasure signal is applied to a rotary erasure head 2 via an analog switch 13 and a signal is erased once during the two field periods by two tracks each by the rotary erasure head FE in the SP mode. On the other hand, a low level signal is outputted from a system controller 3 in the LP mode and a capstan control circuit 4 drives a capstan 5 at a speed a half of the speed at the SP mode. Further, an AND gate 16 outputs AND between an output of an MM 10 and an output of a flip-flop 15 frequency-dividing an output of a rectangular wave signal generating circuit 8 into 1/2 to control the analog switch 13 via an OR gate 12. The erasure current flows once in four field period but the erasure head FE erases all tracks.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a rotary head type recording device, and more particularly to a rotary head type recording device that records information signals by diagonally tracing a tape-shaped recording medium with a rotary head. It is something.

<Summary of the Disclosure> The present specification and drawings describe an apparatus for recording information signals by diagonally tracing a tape-shaped recording medium with a rotary head, and for setting a plurality of pitches of tracks on which the information signals are recorded. When changing the running speed in the longitudinal direction of the tape-shaped recording medium, the amount of erase current supplied to the rotary erase head that traces the medium in the same direction as the head and performs erasing is changed. The present invention discloses a technology for obtaining a rotary head type recording device that enables erasing of the recording medium by supplying a minimum amount of erasing current, thereby reducing adverse effects on recorded signals, and consuming less power. .

<Prior Art> A well-known rotary head type recording device of this type is the video tape recorder (VTR), but in recent years, VTRs have become smaller and have higher recording density, and so-called video tape recorders using 8 mm wide magnetic tape have been developed. 8mm VTRs are also being put into practical use.

These lightweight VTRs are often used outdoors, so it is strongly desired that they have editing functions such as inserts for so-called splice shots, and in response to this, rotating erasing heads that leave less erased data are being used. By the way, tapes with high coercive force, such as so-called metal tapes, are used as magnetic recording media with the trend toward higher density recording. In order to erase this high coercivity magnetic tape, it is necessary to increase the erasing current of the rotary erasing head.

(Problems to be Solved by the Invention) On the other hand, with the aim of achieving even higher density magnetic recording, there are VTR models that can set a plurality of track pitches. In such a model, especially when recording with a narrow track pitch, the power consumption due to the erase current increases.

Additionally, as drums become smaller, it is possible that the erase current will flow into other heads via the rotary transformer, and this effect will appear as a deterioration in playback image quality, especially when recording with a narrow track pitch. It was something to put away.

SUMMARY OF THE INVENTION In view of the drawbacks typified above, it is an object of the present invention to provide a recording device with a rotary head that reduces the negative influence of erase current on recording signals and consumes less power.

(Means for Solving the Problems) In view of the above object, the present invention provides an apparatus for recording information signals by diagonally tracing a tape-shaped recording medium with a rotary head. When switching the running speed in the longitudinal direction of the tape-shaped recording medium in order to set a plurality of pitches, the amount of erasing current supplied to the rotating erasing head that traces the medium in the same direction as the head for erasing is switched. Configured.

(Function) By configuring as described above, it is possible to erase the recording medium by supplying the minimum necessary erasing current, thereby reducing the negative influence on the recorded signal and reducing power consumption. became possible.

(Embodiment) FIG. 1 is a diagram showing the configuration of a VTR as an embodiment of the present invention. In the figure, 1 is a magnetic tape, 2 is a rotating drum, and the rotating drum 2 includes recording heads A, B, and Erase head F
E is mounted on the rotating drum 2.

FIG. 2 is a diagram showing the arrangement of heads on the rotating drum in the VTR shown in FIG. 1. As shown in FIG.
are attached with a phase difference of 180° from each other, and the one-rotation erasing head FE is attached to both of these recording heads A and H by 90°.
They are installed with a phase difference of .

FIGS. 3(A) and 3(B) are diagrams showing trap patterns recorded on a magnetic tape by the VTR shown in FIG. Figure 3 (B) shows a mode (hereinafter referred to as SP) in which recording is performed using a narrow track pitch (TW2).
Hereinafter, the track pattern according to LP) is shown.

Now, if 7w is twice Tw2, then one rotation of the erasing head F
The width of E (FEw) is more than twice that of TwI, and accordingly, more than four times that of Tw2.

Note that Hw indicates the width of head A and head B.

Now, when recording with SP, a high level (Hf) signal is supplied from the system controller 3 to the capstan control circuit 4, and while the rotary drum 2 rotates once, the tape
The rotational speed of the capstan 5 is determined so that the capstan 5 travels an amount corresponding to 2 T w 1. A pinch roller 6 is pressed against the capstan 5.

Reference numeral 7 designates a rotation detector for the drum 2, and its detection output is shaped into a rectangular wave signal as shown in FIG. 4(1) by a rectangular wave signal generating circuit 8. This rectangular wave corresponds to one revolution of the rotating drum 2.
This is the frequency of the period, and the 4th in mono multi (MM) 9 that triggers on the rising edge and MMIO that triggers on the falling edge.
It is assumed to be a rectangular wave as shown in Figure (2). The output of MMIO controls an analog switch 13 via an AND gate 11 and an OR gate 12 in the SP.

Since the erase signal generated by the erase signal generating circuit 14 is supplied to the rotary erase head 2 via the analog switch 13, the erase current at the SP becomes as shown in FIG. 4(3). At this time, the video signal input from the terminal 17 is converted into a signal form suitable for recording by the video signal processing circuit 18, and is recorded one field per track by heads A and B.

At this time, in SP, the rotary erasing head FB erases at least two tracks at a time, once every two fields.

At this time, the rotary erasing head FE erases each track in advance of the recording heads A and B, as shown in FIG. 3(A).

In FIG. 3, Y indicates the tracing direction of the head and the running direction of the tape, respectively.

On the other hand, in LP, the system controller 3 outputs a low level (LO) signal, and the capstan control circuit 4 rotates the capstan 5 at 1/2 the speed of 51 o'clock. Also, the output of the AND gate 11 is always LO, and instead of this, the output of the AND gate 16 is the output of the MMIO (
(shown in FIG. 4 (2)) and the output of the flip-flop (FF) 15 (shown in FIG. 4 (4)) that divides the output of the rectangular wave signal generation circuit 8 into half. Print the output of . The output of this AND gate 16 controls an analog switch 13 via an OR game 12. Therefore, in the LP, an erase current as shown in FIG. 4(5) flows through the erase head FE.

At this time, the erase current is applied only once every four fields, but the erase head FE erases all tracks.

According to the VTR described above, the erase current in the LP is S
In addition to the period being 1/2 that of P, the erase head can also be used for LP and SP, power consumption is halved, and the configuration can be simplified.

Also, the period during which the erase current flows is 1 of SP during LP.
/2, the chance of having an adverse effect on the recording signal due to crosstalk of the rotary transformer is reduced to 1/2, making it possible to perform good recording.

FIG. 5 is a diagram showing the configuration of a VTR as another embodiment of the present invention. Components similar to those in FIG. In the VTR shown in Figure 5, 5
The operation at 1 o'clock is exactly the same as that of the VTR shown in FIG. 1, and the erase current shown in FIG. 6(b) is supplied to the erase head FE.

Incidentally, FIG. 6(a) shows the output of the rectangular wave signal generation circuit 8.

At the time of LP, the analog switch 13 is controlled by the output of MMlo in the same manner as at time 51, but the level control circuit 20 divides the erase signal into 1/2. This is based on the idea that since there are two opportunities for erasing on one track with the erasing head FE, erasing is possible with an erasing current that is 1/2 that of SP.

Needless to say, in the VTR shown in FIG. 5, the power consumption for erasing current during LP is reduced, and the adverse effect on recording signals is also reduced.

Note that the number of recording heads and erasing heads and their arrangement are not limited to those in the above-described embodiments, and the same applies when the present invention is applied to a VTR having recording heads dedicated to SP and LP, respectively. The effect of this can be obtained.

(Effects of the Invention) As described above, according to the present invention, it is possible to obtain a rotary head type recording device that reduces the adverse influence of the erase current on the recording signal and consumes less power.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a schematic configuration of a VTR as an embodiment of the present invention, Fig. 2 is a diagram showing a head arrangement of the VTR shown in Fig. 1, Fig. 3 (A), CB) t * Fig. 1 (7) VTR4
: A diagram showing a J-nil recording pattern. FIG. 4 is a timing chart showing the operation of the VTR shown in FIG. 1, FIG. MS5 is a diagram showing the configuration of a VTR as another embodiment of the present invention, and FIG. This is a timing chart. 1 is a magnetic tape, 2 is a rotating drum, 3 is a system controller, 4 is a capstan control circuit, 5 is a capstan, 11 and 16 are AND gates, 13 is an analog switch, 14 is an erase signal generation circuit, and 20 is a level Control circuit, A and B are recording heads, FE is a rotary erasing head, T
wl. 7w2 indicate mutually different track pitches.

Claims (1)

[Claims] A device for recording an information signal by tracing a tape-shaped recording medium in a diagonal direction with a rotating head, comprising a rotating erasing head for tracing the medium in the same direction as the head for erasing, Rotary head type recording characterized in that when switching the traveling speed in the longitudinal direction of the tape-shaped recording medium in order to set a plurality of pitches of tracks on which signals are recorded, the amount of erasing current supplied to the erasing head is switched. Device.